The measurement of rotation angle is required in various applications, such as manual electrical switches or position detection of a motor. Depending on cost and accuracy constraints, this task can be accomplished by various methods, such as mechanical contacts, optical encoders, or magnetic encoders. Modern integrated circuit technology offers the possibility to integrate magnetic sensors and their readout and angle calculation electronics on one die. This allows embodiments of detectors of mechanical rotation which consist of a permanent magnet attached to the rotor and monolithically integrated sensor means attached to a stator, at competitive cost, yet good performance. The absence of mechanical contact between the rotor with the magnet and the stator with the sensor means allows for hermetic encapsulation of the sensor means. This permits wear free angle measurements under harsh environmental conditions.
The robustness of the angle measurement against mechanical tolerances, against device variation, and against external electromagnetic fields, while keeping fabrication cost low, is a major performance criterion.